There have been significant developments in techniques for measuring immunological substances, such as, anti-bodies, hormones, medicines, drugs, and various other components in blood, measurements of the smallest possible amounts. The primary techniques used to detect these substances are based on labeling, where primary ligands with labels are attached to the substance of interest. The detection of these labels conveys the presence or absence of the target substance. A wide variety of labeling techniques is used for this purpose such as chemical labels, radiolabels, dye labels, etc. However, these techniques are inherently expensive, non-portable, and have environmental side effects.
U.S. Pat. No. 4,313,734 relates to a method, test kit, and labeled component for the detection and or determination of one or more components of the reaction between a specific binding protein and the corresponding bindable substance. One or more labeled components are used that are obtained by coupling particles of a dispersion of a metal, metal compound, or polymer nuclei, coated with a metal or metal compound, having a particle size of at least 5 nm, directly or indirectly to the desired component of the reaction.
U.S. Pat. No. 7,005,108, and patent publication numbers 2003/0192780 and 2006/0096866 relate to methods and insulator electrode devices for performing electrochemical reactions. The devices consist of high specific surface area electrodes based on a channeled conducting base material but has been coated with an organic or inorganic insulating film or multiple layers of such films. The chemical reactions are exemplified by exciting one or several label compounds into an excited state which is spontaneously de-excited by emission of ultraviolet, visible or infrared lights in aqueous solution.
U.S. patent publication number 2003/0124733 relates to a method for preserving a sample. The device include microarrays, slides and membranes. The preservation is achieved by applying a coating composition to a sample or sample device and curing the coating composition.
U.S. Pat. No. 4,725,140 relates to a coherent light beam made incident upon a cell via a polarizer. In the cell is contained a reaction liquid consisting of fine magnetic particles having an anti-body coated thereon and a sample containing an antigen which is specifically reacted with the anti-body on the particles. The particles are rotated in the reaction liquid by means of alternating magnetic fields having a frequency and generated by coils arranged beside the cell. Light scattered by the particles is made incident upon a photo detector via polarizer whose polarization plane is perpendicular to that of the analyzer. An output signal from the photo detector is synchronously detected by means of a reference signal having a frequency. Then a synchronously detected output signal represents an amount of the antigen contained in the sample.
U.S. Pat. No. 4,267,509 relates to a magneto-optical device, which is responsive to magnetic fields by means of a Tyndall Effect in a particular direction exhibited by aligned magnetic colloidal particles suspended in an illuminated liquid medium. The liquid medium is contained in a transparent vessel and has magnetic particles in a very low density, such that the liquid is substantially transparent to the naked eye. A light source is positioned to illuminate the liquid medium and a light-sensing device or photocell is positioned to receive light scattered by the magnetic particles. The light-sensing device is positioned at a predetermined angle from the paraxial direction of the light source. All colloidal solutions, when illuminated by a beam of light, exhibit the Tyndall Effect, i.e. a visible scattering of light by colloidal particles. When the magnetic colloidal solution of this device is brought into the presence of a magnetic field, the magnetic particles become aligned, causing the directed scattering of light called herein the Directional Tyndall Effect, which scattering can be detected by the photocell. In order to minimize the effects of surrounding light, the vessel containing the liquid medium can be enclosed in an opaque container with the photocell and light source mounted in appropriate apertures. For use in varying applications, two photocells can be provided, with the photocells and light source in an orthogonal arrangement.
U.S. Pat. No. 6,855,556 relates to compositions of mutated binding proteins containing reporter group, analyte biosensor devices derived therefrom, and their use as analyte biosensor both in vivo and in vitro. The invention provides a glucose biosensor for in vivo or in vitro use having at least one mutated binding protein and at least one reporter group attached thereto such that the reporter group provides a detectable and reversible signal change when the mutated binding protein is exposed to varying glucose concentrations, wherein the detectable and reversible signal change is related to the varying concentrations.
U.S. Pat. No. 4,812,767 relates to an optical apparatus using a strong magneto-birefringence of magnetic fluid. An external magnetic field is applied in the perpendicular direction to the propagation of the light beam, making the magnetic fluid thin film possess a birefringence property. The apparatus can be used for detecting a magnetic field and can be used as a magnetic field sensor and transformer.
U.S. Pat. No. 5,333,495 relates to a method and apparatus for detecting a photo acoustic signal which includes the steps of modulating the intensity of light obtained from a light source at a predetermined modulation frequency, exciting a specimen by directing the intensity-modulated light onto the specimen. This generates a photo acoustic effect in the specimen.
U.S. Pat. No. 6,437,563 relates to a method and apparatus for measuring combinations of magnetic particles combined by analytes whose amount or other characteristic quality is to be determined.